1. Field of the Invention
The present invention relates to a method for controlling ring volume of a telephone and in particular, a method for controlling the ring volume of the telephone by memorizing the ring volume in a state where a telephone call is answered responsive to a ring tone of the telephone and then, generating the ring tone with the memorized ring volume when the next telephone call and responsive ring tone occurs.
2. Description of the Related Art
Generally, the telephone informs a user thereof of generation of a telephone call by generating a ring tone in response to the incoming telephone call. At this time, the user can control ring volume by utilizing a ring volume controlling unit installed in the telephone. As a result, if a low ring volume is set in the telephone, the user can not hear the ring tone of the telephone when the user is far away from the telephone or there is loud noise around him/her. To solve the problem of loud noise, a device for controlling ring volume is described in U.S. Pat. No. 4,076,968 to Blake Wattenbarger entitled Telephone Ringer Intensity Control Responsive To Ambient Noise wherein a ringer is responsive to a noise measuring circuit is control the loudness of the ringer. The control signal generated by the noise measuring circuit also includes a measurement of noise caused by ring bursts of a predetermined time interval.
Another exemplary device for controlling ring volume of a telephone includes: a tone ringer using a common tone ringer integrated circuit (IC) for generating the ring tone representative of reception of a telephone call in correspondence with an input of a ring signal from a telephone line; a ring detector connected to the telephone line for detecting the ring signal input from the telephone line and then, providing a ring detection signal to a central processing unit; a hook detector for detecting whether the telephone is under an on-hook state or an off-hook state through an operational state of a hook switch and then, providing the detected state of the telephone to the central processing unit; the central processing unit outputs a control signal to control terminals of a multiplexer to gradually increase the ring volume level according to the number of ring signals that are detected by the ring detector; The multiplexer selects the level of the ring tone output from the tone ringer in response to the control signal output by the central processing unit, thereby outputting a selected tone level to an amplifier; and the amplifier amplifies the level of the ring tone selected and outputted from the multiplexer, thereby transmitting the amplified the level thereof to a speaker. When a ring signal is applied via the telephone line, the tone ringer controls the ring volume and generates the ring tone, thereby outputting the generated ring tone. At this time, if the ring signal is detected from the ring detector, the central processing unit controls the multiplexer, thereby selecting the level of the ring tone generated from the tone ringer and then, the selected output level is provided to the speaker via the amplifier. The multiplexer selects the lowest ring tone of the kinds of the ring tone inputted through a plurality of resistors coupled to a single node an then, outputs the selected lowest ring tone thereof. After that, if the user does not answer the telephone call the central processing unit controls the multiplexer in order that the ring tone gradually rings loudly accordingly to the number of ring signals detected by the ring detector.
When an initial ring occurs, however, the exemplary device described above gradually increases the ring tone from the lowest ring tone. As a result, there is a problem with the device for controlling ring volume in that, when the initial ring occurs in condition that the user is far away from the telephone, the user can not hear the ring tone. Also, in spite of the generation of the ring tone, it may be easy to give others unpleasant feeling since the user can not hear the ring tone until the ring tone is gradually increased according to the number of rings, thereby answering the telephone call late.